通讯机构：
[Peng, AG ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
(137)Cs;(239+240)Pu;Distribution characteristics;Lake East dongting;Lake sediments
摘要：
Plutonium-239+240 and (137)Cs in the environment can usually be used to track the impact of nuclear activities on the environment, and have become important tools in environmental geochemical studies. In this study, nine sediment cores (E1-E9) in Lake East Dongting were collected and measured for the activity concentration of (239+240)Pu, (137)Cs and the atomic ratio of (240)Pu/(239)Pu, and then their vertical distribution characteristics were analyzed. The results show that: the activity concentrations of (137)Cs and (239+240)Pu in Lake East Dongting ranged from 5.26±0.43 to 28.6±2.23 Bq kg(-1) and 0.29±0.02 to 1.37±0.09 Bq kg(-1), with an average of 7.48±0.68 Bq kg(-1) and 0.39±0.03 Bq kg(-1), respectively. The atomic ratios of (240)Pu/(239)Pu are 0.168±0.012-0.211±0.015, which are basically consistent with the global atmospheric deposition. The vertical profiles of (137)Cs and (239+240)Pu in sediment cores show obvious single-peak distribution in E1-E6 and bimodal distribution in E7-E9. The results of sedimentation rates calculated by (137)Cs and (239+240)Pu method ranged from 0.59cm y(-1) to 1.99cm y(-1) with a mean of 1.18cm y(-1) and 0.61cm y(-1) to 2.18cm y(-1) with a mean of 1.26cm y(-1). The inventories of (137)Cs and (239+240)Pu in nine sediment cores are 5.87-10.8 kBq m(-2) and 307-545 Bq m(-2), which are about 8-14 and 9-15 times the inventory in the global average atmospheric deposition at the same latitude respectively. Comparing the results of the sedimentation rates and the inventories from different sampling points indicates that extreme climatic events and human activities have a significant impact on sediment environment of Lake East Dongting.
期刊：
Journal of Environmental Radioactivity,2024年272:107331 ISSN：0265-931X
通讯作者：
Hong, CS
作者机构：
[Wen, Jiale; Xie, Bingbing; Hong, CS; Hong, Changshou; Wang, Hong; Wang, Yuhang] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Wang, Hong] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Wen, Jiale; Xie, Bingbing; Hong, Changshou; Wang, Hong; Wang, Yuhang] Univ South China, Hunan Prov Engn Technol Res Ctr Uranium Tailings T, Hengyang 421001, Peoples R China.
通讯机构：
[Hong, CS ] U;Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
Numerical simulation;Radon concentration field;Ramp;Temperature field
摘要：
By introducing the parameters of radon exhalation rate and radon diffusion coefficient, the distribution of radon concentration field on ramp under the condition of superposition of temperature field and flow field is simulated. The simulation results show that the distribution of radon concentration in the ramp under the condition of low-speed ventilation is greatly affected by the temperature field and flow field, and the change of radon exhalation caused by temperature is the main factor leading to the change of radon concentration in the ramp. The change of temperature will cause the overall increase of radon concentration in the ramp. Under the condition of constant flow field, the radon concentration in the chamber is more than two times higher than the average radon concentration in the ramp. Some areas severely exceeded the limit.
作者机构：
[Fujita, Toyohisa; Dong, Haoran; Xu, Sizhi; Wang, Youbin; Gao, Feng; Li, Zengyuan; Hu, Fengtao] Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, MOE Key Laboratory of New Processing Technology for Non-ferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China;[Ning, Shunyan] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: ningshunyan@usc.edu.cn;[Chen, Lifeng] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: lfchen@usc.edu.cn;[Wei, Yuezhou; Hamza, Mohammed F; Yin, Xiangbiao] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China;[Wei, Yuezhou] School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, China
通讯机构：
[Shunyan Ning; Lifeng Chen] S;School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China
摘要：
Efficient recognition, separation and recovery of palladium from high-level liquid waste (HLLW) not only helps the safe, green and environmentally friendly disposal of nuclear waste, but also is an essential important supplement to overcome the growing shortage of natural palladium resources. Herein, a novel silica-based functional adsorbent named 2AT-SiAaC was prepared by a two-step method, i.e., grafting of 2-aminothiazole (2AT) via the amidated reaction after in-situ polymerization of acrylic monomers on porous silica. SEM, EDS, TG-DSC, BET and PXRD all proved the successful preparation of 2AT-SiAaC, and it exhibited ultrahigh adsorption selectivity for Pd(II) (K(d) (distribution coefficient)≥10,344.2mL/g, SF(Pd/M) (separation factor)≥613.7), fast adsorption kinetics with short equilibrium time (t≤1h) and good adsorption capacity (Q≥62.1mgPd/g). The dynamic column experiments shows that 2AT-SiAaC achieved efficiently separation of Pd(II) from simulated HLLW, and the enrichment coefficients (C/C(0)) of Pd(II) was as high as about 14 with the recovery rate nearly 99.9% and basically kept the same performance in three adsorption-desorption column cycle experiments. The adsorption mechanism was analyzed by FT-IR, XPS and DFT calculations, and the ultrahigh selectivity of 2AT-SiAaC was attributed to the preferred affinity of the soft N-donor atoms in 2AT for Pd(II). NO(3)(-) ions participated in the adsorption reaction to keep charge balance, and the frontier orbital electron density distribution diagram shows the charge transfer in the process of material preparation and adsorption. To sum up, 2AT-SiAaC adsorbent provided a new insight for precise recognition and efficient separation of Pd(II) from HLLW.
期刊：
Journal of Environmental Management,2024年353:120283 ISSN：0301-4797
通讯作者：
Shunyan Ning<&wdkj&>Ji Wang
作者机构：
[Wang, Xinpeng; He, Chunlin; Fujita, Toyohisa; Wu, Kun; Zhong, Yilai; Li, Zengyuan] State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, and School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, China;[Ning, Shunyan] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: ningshunyan@usc.edu.cn;[Wang, Ji] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China. Electronic address: wangji_jenny@163.com;[Wei, Yuezhou; Hamza, Mohammed F; Yin, Xiangbiao; Chen, Lifeng] School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China;[Wei, Yuezhou] School of Nuclear Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai, 200240, China
通讯机构：
[Shunyan Ning; Ji Wang] S;School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, China
关键词：
Adsorption and separation;Co-Nd-Dy;DFT calculations;DPPA/CaALG;NdFeB
摘要：
The recovery of rare earth elements (REEs) including neodymium (Nd) and dysprosium (Dy) from NdFeB permanent magnets has become one of the main ways to solve the increased demand for rare earth. Herein, n-dodecyl phosphate (DPPA) was used for the first time as the adsorption functional group donor, sodium alginate as the substrate, and calcium chloride solution as the reactive solvent, a hybrid hydrogel adsorbent DPPA/CaALG was synthesized by sol-gel method for application in the adsorption and separation of Nd and Dy from the Co-Nd-Dy ternary system. SEM-EDS, and N(2) adsorption-desorption analysis showed the successful preparation of DDPA/CaALG with mesoporous structure. Batch experiments showed the superiority of the hybrid hydrogel for the good selective adsorption of Nd and Dy, such as large adsorption capacity (Nd: 162.5mg/g, Dy: 183.5mg/g), and no adsorption for Co. FT-IR, XPS showed that PO and P-O groups are involved in the adsorption process of Nd and Dy as electron acceptors, where the ion exchange of P-OH is dominant. Furthermore, the chemical properties of ligands and complexes were analyzed by Density Functional Theory (DFT) calculations and revealed their adsorption behaviors as well as the competition between different metal ions.
摘要：
This study aims to utilize a hybrid approach of phantom correction and deep learning for synthesized CT (sCT) images generation based on cone-beam CT (CBCT) images for nasopharyngeal carcinoma (NPC). 52 CBCT/CT paired images of NPC patients were used for model training (41), validation (11). Hounsfield Units (HU) of the CBCT images was calibrated by a commercially available CIRS phantom. Then the original CBCT and the corrected CBCT (CBCT_cor) were trained separately with the same cycle generative adversarial network (CycleGAN) to generate SCT1 and SCT2. The mean error and mean absolute error (MAE) were used to quantify the image quality. For validations, the contours and treatment plans in CT images were transferred to original CBCT, CBCT_cor, SCT1 and SCT2 for dosimetric comparison. Dose distribution, dosimetric parameters and 3D gamma passing rate were analyzed. Compared with rigidly registered CT (RCT), the MAE of CBCT, CBCT_cor, SCT1 and SCT2 were 346.11 & PLUSMN; 13.58 HU, 145.95 & PLUSMN; 17.64 HU, 105.62 & PLUSMN; 16.08 HU and 83.51 & PLUSMN; 7.71 HU, respectively. Moreover, the average dosimetric parameter differences for the CBCT_cor, SCT1 and SCT2 were 2.7% & PLUSMN; 1.4%, 1.2% & PLUSMN; 1.0% and 0.6% & PLUSMN; 0.6%, respectively. Using the dose distribution of RCT images as reference, the 3D gamma passing rate of the hybrid method was significantly better than the other methods. The effectiveness of CBCT-based sCT generated using CycleGAN with HU correction for adaptive radiotherapy of nasopharyngeal carcinoma was confirmed. The image quality and dose accuracy of SCT2 were outperform the simple CycleGAN method. This finding has great significance for the clinical application of adaptive radiotherapy for NPC.
作者：
Nie, Pei;Yang, Guangjie;Wang, Yanmei;Xu, Yuchao;Yan, Lei;...
期刊：
European Radiology,2023年33(12):8858-8868 ISSN：0938-7994
通讯作者：
Wang, X.;Wang, Z.
作者机构：
[Nie, Pei] Department of Radiology, the Affiliated Hospital of Qingdao University, Qingdao, Shandong, China;[Yan, Lei; Yang, Guangjie] Department of Nuclear Medicine, the Affiliated Hospital of Qingdao University, No. 59, Haier Road, Qingdao, 266061, Shandong, China;[Wang, Yanmei; Duan, Shaofeng] GE Healthcare, Shanghai, China;[Xu, Yuchao] School of Nuclear Science and Technology, University of South China, Hengyang, Hunan, China;[Zhang, Mingxin] Department of Urology, the Affiliated Hospital of Qingdao University, Qingdao, Shandong, China
通讯机构：
[Wang, Z.; Wang, X.] D;Department of Radiology, No. 324 Jingwu Road, Shandong, China;Department of Nuclear Medicine, No. 59, Haier Road, Shandong, China
通讯机构：
[Yanliang Tan] C;College of Physics and Electronic Engineering , Hengyang Normal University, Hengyang, Hunan Province 421008, China
摘要：
Radon-222 (Rn-222) exhalation rate is vital for estimating radiation risk from many kinds of materials. AlphaGUARD measures the radon concentration based on the ionization chamber principle, which is currently recognized as a reference instrument to measure radon. In China, measurements of radon exhalation rate are performed by AlphaGUARD operated in flow-through mode on a reference device to verify measurement accuracy. These measurements are performed in both open and closed loop. AlphaGUARD can fast rapidly the variation of the radon concentration in the chamber, which is tightly pressed against the surface of the medium to accumulate the exhaled radon. When the model is used to obtain the radon exhalation rate, the radon exhalation rates obtained by nonlinear data fitting on the measured radon concentrations are similar to the reference value of the device. The difference of radon exhalation rate values of six measurements is small.
期刊：
International Journal of Biological Macromolecules,2023年253(Pt 4):126884 ISSN：0141-8130
通讯作者：
Elwakeel, KZ
作者机构：
[Ahmed, Marwan M.; Akhdhar, Abdullah; Elwakeel, Khalid Z.; Khan, Ziya A.; Sulaiman, Mohamed G. M.; Alghamdi, Huda M.] Univ Jeddah, Coll Sci, Dept Chem, Jeddah, Saudi Arabia.;[Elwakeel, Khalid Z.] Port Said Univ, Fac Sci, Environm Sci Dept, Environm Chem Div, Port Said, Egypt.;[Hamza, Mohammed F.] Univ South China, Sch Nucl Sci & Technol, Heng Yang 421001, Peoples R China.;[Hamza, Mohammed F.] Nucl Mat Author, POB 530, Cairo, Egypt.
关键词：
Flow rate;Gum Arabic-alginate;Heavy metal extraction;Polysaccharides;Well water
摘要：
The change of composition of an adsorbent material has been widely used as a method to increase its adsorption capacity, particularly concerning adsorbents made of polysaccharides. Introducing magnetic adsorbents into contaminated water treatment systems is a highly promising strategy, as it promotes the metal ions removal from water. Considering this, gum Arabic (GA) was associated with alginate (Alg), when magnetite nanoparticles were present or absent, to produce beads that were utilised to take up Cu(II), Cd(II), and Pb(II) from aqueous solution. After a complete characterisation (for which Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and swelling were used), the adsorption properties were established using batch and column tests. The magnetic beads (MAlg/GA) demonstrated improved adsorption in comparison with the beads made without magnetite (Alg/GA) under the same conditions. In normal adsorption conditions (pH6.0, 25°C, 2.5gL(-1) of adsorbent dosage), the highest uptake capacities recorded for the MAlg/GA beads were: for Cu(II), 1.33mmolg(-1); Cd(II), 1.59mmolg(-1); and for Pb(II), 1.43mmolg(-1). The pseudo-second-order kinetics and Langmuir isotherm models provided good fits for the adsorption of these metals. Overall, ion exchange and physical forces led to the uptake of these metals by both Alg/GA and MAlg/GA; moreover, the functional groups on the beads played crucial roles as binding sites. Additionally, it was observed that flow rates of >2mLmin(-1) did not produce noticeable changes in uptake levels over the same flow period. It was found that the efficient eluting agent was HNO(3) (0.2M). In some cases, the metals were not removed fully from the used beads during the first five cycles of regeneration and reuse. The results of this investigation show that these beads are efficient adsorbents for the removal of metal ions from spiked well water samples.
摘要：
To address the imperative need for efficient removal of uranium-containing wastewater and mitigate radioactive contamination risks associated with nuclear energy, the development of materials with high removal efficiency and facile separation is crucial. This study designed and synthesised MnO(2)@chitosan (CTS) composite aerogel beads by in-situ growing δ-MnO(2) on porous CTS aerogel beads. This approach not only mitigates the agglomeration of MnO(2) nanospheres but also significantly enhances the porous structure and surface area of MnO(2)@CTS. These cost-effective and eco-friendly millimeter-scale spherical aerogels exhibited convenient separation properties after adsorption. These characteristics help mitigate the risk of equipment seam blockage and secondary pollution that are often associated with powdered adsorbents. Additionally, MnO(2)@CTS exhibited remarkable mechanical strength (stress approximately 0.55MPa at 60% strain), enabling rapid separation and easy regeneration while maintaining high adsorption performance even after five cycles. Significantly, MnO(2)@CTS exhibited a maximum adsorption capacity of 410.7mg/g at pH 6 and 298K, surpassing reported values for most CTS/MnO(2)-based adsorbents. The chemisorption process of U(VI) on MnO(2)@CTS followed the pseudo-second-order kinetic and Dubinin-Radushkevish models. X-ray photoelectron spectroscopy analysis further confirmed the reduction of U(VI) to U(V/IV). These findings highlight the substantial potential of MnO(2)@CTS aerogel beads for U(VI) removal from aqueous solutions, positioning them as a promising solution for addressing U(VI) contamination in wastewater.
摘要：
This study aimed to assess the feasibility of using magnetic resonance imaging (MRI)-based Delta radiomics characteristics extrapolated from the Ax LAVA + C series to identify intermediary- and high-risk factors in patients with cervical cancer undergoing surgery following neoadjuvant chemoradiotherapy. A total of 157 patients were divided into two groups: those without any intermediary- or high-risk factors and those with one intermediary-risk factor (negative group; n = 75). Those with any high-risk factor or more than one intermediary-risk factor (positive group; n = 82). Radiomics characteristics were extracted using Ax-LAVA + C MRI sequences. The data was divided into training (n = 126) and test (n = 31) sets in an 8:2 ratio. The training set data features were selected using the Mann-Whitney U test and the Least Absolute Shrinkage and Selection Operator (LASSO) test. The best radiomics features were then analyzed to build a preoperative predictive radiomics model for predicting intermediary- and high-risk factors in cervical cancer. Three models-the clinical model, the radiomics model, and the combined clinic and radiomics model-were developed in this study utilizing the random forest Algorithm. The receiver operating characteristic (ROC) curve, decision curve analysis (DCA), accuracy, sensitivity, and specificity were used to assess the predictive efficacy and clinical benefits of each model. Three models were developed in this study to predict intermediary- and high-risk variables associated with postoperative pathology for patients who underwent surgery after receiving neoadjuvant radiation. In the training and test sets, the AUC values assessed using the clinical model, radiomics model, and combined clinical and radiomics models were 0.76 and 0.70, 0.88 and 0.86, and 0.91 and 0.89, respectively. The use of machine learning algorithms to analyze Delta Ax LAVA + C MRI radiomics features can aid in the prediction of intermediary- and high-risk factors in patients with cervical cancer receiving neoadjuvant therapy.
摘要：
OBJECTIVE: To compare intensity reduction plans for liver cancer with or without a magnetic field and optimize field and subfield numbers in the intensity-modulated radiotherapy (IMRT) plans designed for liver masses in different regions. METHODS: This retrospective study included 62 patients who received radiotherapy for liver cancer at Shandong Cancer Hospital. Based on each patient's original individualized intensity-modulated plan (plan(1.5T)), a magnetic field-free plan (plan(0T)) and static intensity-modulated plan with four different optimization schemes were redesigned for each patient. The differences in dosimetric parameters among plans were compared. RESULTS: In the absence of a magnetic field in the first quadrant, PTV D(min) increased (97.75 ± 17.55 vs. 100.96 ± 22.78)%, D(max) decreased (121.48 ± 29.68 vs. 119.06 ± 28.52)%, D(98) increased (101.35 ± 7.42 vs. 109.35 ± 26.52)% and HI decreased (1.14 ± 0.14 vs. 1.05 ± 0.01). In the absence of a magnetic field in the second quadrant, PTV D(min) increased (84.33 ± 19.74 vs. 89.96 ± 21.23)%, D(max) decreased (105 ± 25.08 vs. 104.05 ± 24.86)%, and HI decreased (1.04 ± 0.25 vs. 0.99 ± 0.24). In the absence of a magnetic field in the third quadrant, PTV D(max) decreased (110.21 ± 2.22 vs. 102.31 ± 26)%, L-P V(30) decreased (10.66 ± 9.19 vs. 5.81 ± 3.22)%, HI decreased (1.09 ± 0.02 vs. 0.98 ± 0.25), and PTV D(min) decreased (92.12 ± 4.92 vs. 89.1 ± 22.35)%. In the absence of a magnetic field in the fourth quadrant, PTV D(min) increased (89.78 ± 6.72 vs. 93.04 ± 4.86)%, HI decreased (1.09 ± 0.01 vs. 1.05 ± 0.01) and D(98) increased (99.82 ± 0.82 vs. 100.54 ± 0.84)%. These were all significant differences. In designing plans for tumors in each liver region, a total number of subfields in the first area of 60, total subfields in the second zone of 80, and total subfields in the third and fourth zones of 60 or 80 can achieve the dose effect without a magnetic field. CONCLUSION: In patients with liver cancer, the effect of a magnetic field on the target dose is more significant than that on doses to organs at risk. By controlling the max total number of subfields in different quadrants, the effect of the magnetic field can be greatly reduced or even eliminated.
作者：
Dai, Jiaona;Wang, Hui;Xu, Yuchao;Chen, Xiyang;Tian, Rong
期刊：
Seminars in Cancer Biology,2023年91:124-142 ISSN：1044-579X
通讯作者：
Xiyang Chen<&wdkj&>Rong Tian
作者机构：
[Wang, Hui; Tian, Rong; Dai, Jiaona] Sichuan Univ, West China Hosp, Dept Nucl Med, Chengdu 610041, Peoples R China.;[Xu, Yuchao] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chen, Xiyang] Sichuan Univ, West China Hosp, Dept Gen Surg, Div Vasc Surg, Chengdu 610041, Peoples R China.
通讯机构：
[Xiyang Chen; Rong Tian] D;Department of Nuclear Medicine, West China Hospital, Sichuan University, Chengdu 610041, China<&wdkj&>Division of Vascular Surgery, Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China
摘要：
Based on the advantages of revealing the functional status and molecular expression of tumor cells, positron emission tomography (PET) imaging has been performed in numerous types of malignant diseases for diagnosis and monitoring. However, insufficient image quality, the lack of a convincing evaluation tool and intra- and interobserver variation in human work are well-known limitations of nuclear medicine imaging and restrict its clinical application. Artificial intelligence (AI) has gained increasing interest in the field of medical imaging due to its powerful information collection and interpretation ability. The combination of AI and PET imaging potentially provides great assistance to physicians managing patients. Radiomics, an important branch of AI applied in medical imaging, can extract hundreds of abstract mathematical features of images for further analysis. In this review, an overview of the applications of AI in PET imaging is provided, focusing on image enhancement, tumor detection, response and prognosis prediction and correlation analyses with pathology or specific gene mutations in several types of tumors. Our aim is to describe recent clinical applications of AI-based PET imaging in malignant diseases and to focus on the description of possible future developments.
摘要：
Various low-concentration inert gases, including 222Rn, 133Xe, and 85Kr, pollute the atmosphere near nuclear facilities (e.g., nuclear power plants or reprocessing plants). Owing to the detection limits of instruments, it has become urgent to determine the concentration of these gases efficiently and perform their online monitoring. However, current technologies are limited by low enrichment efficiencies. In this study, a high-pressure, low-flow, large-volume, and high-efficiency adsorption method has been proposed along with a high-temperature, low-pressure, high-flow, and small-volume rapid desorption and collection method, which are based on the gas enrichment principle of activated carbon. The results demonstrated that when dynamic adsorption was implemented using a two-level enrichment method, the final desorbed gas concentration was proportional to the volume ratio of both the large and small activated carbon beds. At a volume ratio of 15:1, 222Rn concentration increased from 110 to 21,016 Bq m-3 after the two-level enrichment; meanwhile, 222Rn concentration increased from 110 to 42,012 Bq m-3 after three-level enrichment. The three-level enrichment technology provides technical support for the enrichment of low-concentration inert gases in the environment, while offering an important technical foundation for improving the monitoring of low-concentration inert gases in specific environments as well as the atmospheric environment.
通讯机构：
[Tan, YL ] H;Hengyang Normal Univ, Coll Phys & Elect Engn, Hengyang 421008, Hunan, Peoples R China.
关键词：
Accumulation chamber;AlphaGUARD PQ2000PRO;Interference of thoron;RAD7;Radon exhalation model
摘要：
Radon exhalation rate from soil is a critical factor in evaluating environmental radon levels. However, AlphaGUARD PQ2000PRO may have some sensitivity towards thoron, which can have a significant impact on radon measurement. The traditional radon exhalation models generally ignore the presence of thoron, leading to an overestimation of the radon exhalation rate from soil. To handle this issue, a new model was proposed based on an analysis of several previous studies on radon exhalation theories. To prove the feasibility of the model, the radon exhalation rate measurements were performed by two different types of detectors-AlphaGUARD PQ2000PRO and RAD7. The radon exhalation rate obtained by using the new model is in good agreement with that obtained by using the theoretical model of radon exhalation of RAD7 within one standard error. This new model can be applied to accurately measure radon exhalation rate from soil by the PIC detector (PQ2000PRO).
作者：
Hamza, Mohammed F.;Wei, Yuezhou;Khalafalla, Mahmoud S.;Abed, Neveen S.;Fouda, Amr;...
期刊：
Science of The Total Environment,2022年821:153184 ISSN：0048-9697
通讯作者：
Wei, YZ;Guibal, E
作者机构：
[Wei, Yuezhou; Hamza, Mohammed F.] Univ South China, Sch Nucl Sci & Technol, Heng Yang 421001, Egypt.;[Khalafalla, Mahmoud S.; Abed, Neveen S.; Hamza, Mohammed F.] Nucl Mat Author, POB 530, Cairo, Egypt.;[Wei, Yuezhou] Shanghai Jiao Tong Univ, Sch Nucl Sci & Engn, Shanghai, Peoples R China.;[Fouda, Amr] Al Azhar Univ, Fac Sci, Bot & Microbiol Dept, Cairo 11884, Egypt.;[Elwakeel, Khalid Z.] Univ Jeddah, Dept Chem, Coll Sci, Jeddah, Saudi Arabia.
通讯机构：
[Wei, YZ ] U;[Guibal, E ] I;Univ South China, Sch Nucl Sci & Technol, Heng Yang 421001, Egypt.;Shanghai Jiao Tong Univ, Sch Nucl Sci & Engn, Shanghai, Peoples R China.;IMT Mines Ales, Polymers Composites & Hybrids PCH, Ales, France.
关键词：
Application to acidic leachates;Selectivity issues;Sorption kinetics and isotherms;Uranium and thorium sorption and desorption;Urea and thiourea functionalization of silica beads
摘要：
Urea and thiourea have been successfully deposited at the surface of silica beads (through one-pot reaction with formaldehyde) for designing new sorbents for U(VI) and Th(IV) recovery (UR/SiO(2) and TUR/SiO(2) composites, respectively). These materials have been characterized by FTIR, titration, elemental analysis, BET, TGA, SEM-EDX for identification of structural and chemical properties, and interpretation of binding mechanisms. Based on deprotonation of reactive groups (amine, carbonyl, or thiocarbonyl) and metal speciation, the optimum pH was ~4. Uptake kinetics was fast (equilibrium within 60-90 min). Although the kinetic profiles are fitted by the pseudo-first order rate equation, the resistance to intraparticle diffusion cannot be neglected. Sorption isotherms were fitted by Langmuir equation (maximum sorption capacities: 1-1.2 mmol g(-1)). Thermodynamics are also investigated showing differences between the two types of functionalized groups: exothermic for TUR/SiO(2) and endothermic for UR/SiO(2). Metal desorption is highly effective using 0.3-0.5 M HCl solutions: total desorption occurs within 30-60 min; sorption/desorption properties are remarkably stable for at least 5 cycles. The sorbents have marked preference for U(VI) and Th(IV) over alkali-earth and base metals at pH(eq) ~4.8. By preliminary precipitation steps, it is possible "cleaning" ore leachates of pegmatite ore, and recovering U(VI) and Th(IV) using functionalized silica beads. After elution and selective recovery by precipitation with oxalate (Th-cake) and alkaline (U-cake), the metals can be valorized.
作者：
Hamza, Mohammed F.;Guibal, Eric;Althumayri, Khalid;Vincent, Thierry;Yin, Xiangbiao;...
期刊：
Molecules,2022年27(20):7128- ISSN：1420-3049
通讯作者：
Eric Guibal<&wdkj&>Wenlong Li
作者机构：
[Wei, Yuezhou; Hamza, Mohammed F.; Yin, Xiangbiao; Li, Wenlong] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Hamza, Mohammed F.] Nucl Mat Author, POB 530, Cairo 4710030, Egypt.;[Guibal, Eric; Vincent, Thierry] IMT Mines Ales, Polymers Composites & Hybrids, F-30360 Ales, France.;[Althumayri, Khalid] Taibah Univ, Coll Sci, Dept Chem, Al Madinah Al Munawarah 30002, Saudi Arabia.
通讯机构：
[Eric Guibal; Wenlong Li] A;Authors to whom correspondence should be addressed.<&wdkj&>School of Nuclear Science and Technology, University of South China, HengYang 421001, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>Polymers Composites and Hybrids, IMT—Mines Ales, F-30360 Ales, France
关键词：
application to seawater;composite characterization;functionalization for enhanced performance;metal desorption and sorbent recycling;sorption selectivity;strontium recovery;sulfonation of composite algal/PEI sorbent;uptake kinetics and sorption isotherms
摘要：
Sulfonic resins are highly efficient cation exchangers widely used for metal removal from aqueous solutions. Herein, a new sulfonation process is designed for the sulfonation of algal/PEI composite (A*PEI, by reaction with 2-propylene-1-sulfonic acid and hydroxylamine-O-sulfonic acid). The new sulfonated functionalized sorbent (SA*PEI) is successfully tested in batch systems for strontium recovery first in synthetic solutions before investigating with multi-component solutions and final validation with seawater samples. The chemical modification of A*PEI triples the sorption capacity for Sr(II) at pH 4 with a removal rate of up to 7% and 58% for A*PEI and SA*PEI, respectively (with SD: 0.67 g L(-1)). FTIR shows the strong contribution of sulfonate groups for the functionalized sorbent (in addition to amine and carboxylic groups from the support). The sorption is endothermic (increase in sorption with temperature). The sulfonation improves thermal stability and slightly enhances textural properties. This may explain the fast kinetics (which are controlled by the pseudo-first-order rate equation). The sulfonated sorbent shows a remarkable preference for Sr(II) over competitor mono-, di-, and tri-valent metal cations. Sorption properties are weakly influenced by the excess of NaCl; this can explain the outstanding sorption properties in the treatment of seawater samples. In addition, the sulfonated sorbent shows excellent stability at recycling (for at least 5 cycles), with a loss in capacity of around 2.2%. These preliminary results show the remarkable efficiency of the sorbent for Sr(II) removal from complex solutions (this could open perspectives for the treatment of contaminated seawater samples).
通讯机构：
[Xinpeng Wang; Shunyan Ning] S;School of Resources, Environment and Materials, Guangxi Key Laboratory of Processing for Non-ferrous Metallic and Featured Materials, Guangxi University, 100 Daxue Road, Nanning, 530004, PR China<&wdkj&>School of Nuclear Science and Technology, University of South China, 28 Changsheng West Road, Hengyang, 421001, PR China
摘要：
Effective and efficient disposal of radioactive pollution has been crucial for responding to unexpected nuclear accidents and guaranteeing the sustainable development of nuclear energy. In this study, a kind of porous zirconium phosphate was synthesized with a sol-gel process followed by a post-synthesis modification to remove the radioactive Sr(2+) from wastewater. The prepared materials were characterized by different technologies including FT-IR, SEM-EDS, XRD and XPS, and then the adsorption performance was evaluated in batch and column modes. Experimental results suggested that the porous zirconium phosphate adsorbent was successfully prepared with Na(+) dispersed in the channels for exchange. It inherited the excellent properties of zirconium dioxide aerogel and exhibited mesoporous structure and large specific surface area. Compared with traditional zirconium phosphate, the adsorption kinetics and the adsorption capacity were improved simultaneously. Especially, it showed excellent selectivity towards Sr(2+) among different cations, and even could remove the low-level Sr(2+) from natural seawater efficiently, which powerfully demonstrated that the prepared material could be applied in the treatment of practical wastewater. Spectra studies uncovered that the adsorption activities were dominated by the ion exchange mechanism between external Sr(2+) and interlaminar Na(+) or H(+). In conclusion, this paper not only reports a novel synthesis strategy for the acquisition of porous zirconium phosphate, but also presents a promising adsorbent for the Sr(2+) removal.
